Hi,
It seems that you are using MST in your network. Usually you should map many VLANs to one instance and then you will not exceed 64 instances. Try to configure MST by mapping couple of VLANs to one instance, that should work. Following you have an example:
spanning-tree mst configuration
name domain_name
revision 1
instance 1 vlan 1-20
instance 2 vlan 21-50
instance 3 vlan 100,120-150
The other question you should ask yourself as an administrator of that network. Do you really need MST as STP? MST is mostly very usfull in very big networks with plenty of VLANs becouse it reduce CPU and memmory load but it makes the troubleshooting harder. If you need to stay with MST plan it well.
regards:
Michal